Method and apparatus for producing insulating walls



June 21, 1960 F. SCHRODER-STRANZ 2,941,900

METHOD AND APPARATUS FOR PRODUCING INSULATING WALLS Filed Aug. 17, 1955United States Patent METHOD AND APPARATUS FOR PRODUCING INSULATING WALLSFriedrich Schriider-Stranz, Laufenburg, Germany (Sackingerstrasse 28,Laufenburg, Baden, Germany) Filed Aug. 17, 1955, Ser. No. 528,861

Claims priority, application Germany Aug. 19, 1954 6 Claims. (Cl.117-72) The present invention relates to a method of producing sound andheat insulating walls or partitions, and to an apparatus for carryingout such method.

It is in many cases desired to partition larger or smaller rooms bywalls of porous material. For this purpose, prior. to this invention,boards of porous material have been used. However, erecting walls ofsuch material has been found to be a very costly procedure due to thefact that a considerable portion of the material is lost for anypractical purposes when the boards are being fitted to their propersize. Also, when using individual boards, it is necessary to join themto each other, as well as to their supporting structure. For forming,such joints and to fill out the intervening spaces, cracks; and seams, arather thick mass is usually applied which, however, rarely forms asecure and permanent connection.

It is the principal object of the present invention to overcome thisdeficiency of the. prior methods and to form heat or sound insulatingscreens, walls, floors,-or ceilings by applying upon a suitablesupporting base a foamlike substance which solidifies into aself-supporting structure.

Another object of the present invention is to form such self-supportingwalls and the like by spraying the teamlike substance upon the originalsupporting base by means of compressed gas or air.

The present invention presents the great advantage that it permits theformation of large platelike wall surfaces without any seams or joints,either between the individual wall portions or between such walls andadjacent supporting structures. Also, all corners or other places whichdue to the difiiculty of reaching them were by previous methods,improperly sealed, may, by applying the inventive method, be filledoutand sealed securely, and. without any difiiculty.

Further, the materials to be used according to the invention are readilyavailable and applicable at any time, require very little storing spaceand, contrary to readymanufactured wall boards, are easily shipped,carried, stored, and applied without danger of breakage during suchtimes.

The present invention permits the production of insulating walls againstsound, heat, or cold which may be regarded as ideal, and it may beapplied either for coating existing walls with a layer of porousmaterial, for filling out skeleton or screen walls, or for fillinghollow spaces. It is thus of great importance at all points or placeswhere any kind of insulating walls or wall portions are to be built,cracks or seams are to be sealed, or gas-tight closures are to beformed. The foamy substance may, according to the invention, preferablybe sprayed either to form outer wall surfaces or to act as a fillerbetween existing wall surfaces so as to fill out the intervening spacesand to insulate them for various purposes too numerous to be mentionedindividually.

The present invention preferably resides in the application of a foamysubstance which is formed on the spot by means of compressed air of abasic foam solution of any suitable type known as such, a resinous ureasolution, and a catalyst. A great number of foam-forming substances havebeen known for a long time and may be used, such as fatty alcoholsulfate soaps, other soap solutions, solutions of detergents. Thus, forexample, a watery solution of a precondensate of a urea compound andformaldehyde, and a watery foam-forming solution may be used. Thecatalyst for the dissolved, intermediate product of resinous urea, forexample, phosphoric acid or oxalic acid may be added to the foam-formingsolution. The resinous urea constitutes "a hardener or solidifying agentfor the foam produced of the foam-forming solution by means ofcompressed air, and is adapted to solidify or congeal the foam so thatit will permanently retain its original volume and structure.

According to the invention it has been found advisable first to whip upthe foam-producing solution into a foam, and immediately prior to thetime when the foam is being sprayed, to add the resinous solutionthereto as a hardening agent.

The surfaces to be covered with the congealing foam may first beprovided with a thin filmlike coating with high adhesive qualities. Suchadhesive coating which may also be applied by spraying may consist, forexample, of a solution of an acrylic acid polymeride which has beendiluted with water. Such a coating solidly adheres to wood, metal,stone, or synthetic materials, and also adheres tightly to thesprayed-on foam according to the invention, even though such foam maynot be sprayed-on for many hours subsequent to the application of thead-,

hesive coating. Thus, it is possible to apply a layer of solidifiedfoam, for example, on walls, ceilings, and entire buildings, and to sealsuch structures or to build solid walls of porous material in the mostinexpensive and quickest possible manner.

The foam may also be forced into container-like rooms, for example,closed chambers which are provided with an inlet and an outlet opening.It then uniformly permeates the entire hollow space and adheres tightlyon the walls thereof. Thus, for example, doors and windows may bereliably sealed and insulated with very little effort and at a lowexpense. The same applies to pipe lines and channels in walls andceilings.

If framelike supporting or skeleton structures are .provided and suchframes are covered up in a suitable manner, the foam may be sprayedtherein, and, if desired, be

leveled off to form a smooth outer surface. It may, however, also beapplied to a framelike supporting structure in which a suitablelatticework or wire mesh is provided. This will then result in areinforced solidified foam structure which may, for instance, form theceilings of rooms in buildings.

Any exposed solidified foam surfaces may also be coated with a coveringlayer, which may preferably also be done by a spraying method.

Another advantage of the new foam spray consists in the fact that it maybe mixed with a suitable dye substance or a fine-grained filler, orboth. Such admixtures may also contain a suitable coating material, ifdesired.

Further objects, features, and advantages of the present invention willbe apparent from the following detailed description thereof and from theaccompanying drawings which diagrammatically illustrate an apparatuswhich is preferably to be used according to the invention to carry outthe new method, and in which- Fig. 1 shows a plan view of the apparatus;while Fig. 2 shows a side view thereof.

Referring to the drawings, the apparatus as illustrated is operated by asuitable source of compressed air, not shown, for example, an aircompressor or a compressedair bottle. Such compressed air is suppliedthrough a Patented June 21, 1960.

pipe '1 and a second pipe 2, which is. provided with a control valve 3,to a container 4 in which a supply of hardening or solidifying solutionis stored. Pipe 2 further leads to a container 5 in which thefoam-forming solusears stofed' "Container 5 is connected by a hose line8 spray' gun, the tubular handle of which serves as a connection for thehose line 13 and is provided 'with a springcontrolled shutofif valve 14.The forward end of chamber serves as a mixing chamber for mixing thefoam with the solidifying agent. For this purpose, a hose line 7 leadingfrom container 4 and provided with a control valve 9 near the spray gunconnects with chamber 10 near the front end thereof. For obtaining anintimate and uniform mixture of foam and solidifying agent, line 7preferably terminates into chamber 10 at an acute angle. For the samepurpose, the connecting end of line 7 leading the solidifying agent intochamber 10 may also-be provided with a spiral-shaped mixing nozzle.

' The front end of the foam and mixing chamber 10 is provided with aspraying nozzle 11 which may be operated with or without a removableguiding tube 12 for pointing the foam jet in a straight forwarddirection.

As illustrated in the drawings, the compressed air enters into thecontainers 4 and 5 at the top, while the outlet pipes which areconnected to hose lines 7 and 8 are preferably mounted in containers 4and 5, respectively, so as to terminate at a point close to the bottomof the containers. Each of the containers is also provided witha fillinghole 6 which may be securely closed.

The container 10 may be filled with spherical bodies so as to insurethat the foam produced therein will consist of uniformly small bubbles.

Although my invention has been illustrated and described with referenceto the preferred embodiments thereof, I wish to have it understood thatit is in no way limited to the details of such embodiments or to thespecific examples described, but is capable of numerous modificationswithin the scope of the appended claims.

Having thus fully disclosed my invention, what I claim is:

1. Method of rendering objects heat and sound-insulating, comprisingpropelling a foam-forming solution tion of a urea-formaldehydeprecondensate adapted toharden when in contact with said catalyst from asecond storage zone into a oommon'foam-forming and mixing zone by meansof a gaseous pressure medium; introducing said pressure medium into saidcommon zone to form foam and to cause mixing of said foam with saidprecondensate solution; and spraying the mixture produced with the aidof said pressure medium upon the object to be treated, the precondensatesolution being propelled to the common zone immediately prior to thespraying.

2. A method as defined in claim 1, wherein prior to the application ofthe foam, said object is provided with a filmlike coating ofv a-highlyadhesive material.

3. A method as defined in claim 1, wherein said object forms a framelikestructure closed at least at one side, and wherein said foam is forcedunder pressure into said frame to solidify therein.

'4. ,A method as defined in claim 1, whereinsaid object forms a framehaving a latticework therein, and wherein said foam is forced underpressure upon said latticework to solidify thereon and close theinterstices to form a solid wall;

5. A method as defined in claim 1, further comprising the step of addingat least one pigment to the foam before applying the same to saidobject.

6. A method as defined in claim 1, further comprising the step of addinga fine-grained filler to the foam before applying the same to saidobject.

References Cited in the file of this patent UNITED STATES PATENTS2,158,033 McKinney May 9, 1939 2,178,358 Howald et a1 Oct. 31, 19392,432,389 Daly Dec. 9, 1947 2,602,759 Mollo July 8, 1952 2,608,536Sterling Aug. 26, 1952 2,629,698 Sterling Feb. 24, 1953 2,653,139Sterling Sept. 22, 1953 2,695,246 Iurgensen et al. Nov. 23, 19542,705,683 Hazeltine et al. Apr. 5, 1955 2,715,045 Thomson Aug. 9, 19552,747,934 Fisher May 29, 1956 2,823,143 Upperman Feb. 11, 1958 FOREIGNPATENTS 652,705 Great Britain May 2, 1951 OTHER REFERENCES

1. METHOD OF RENDERING OBJECTS HEAT AND SOUND INSULATING, COMPRISINGPROPELLING A FOAM-FORMING SOLUTION CONTAINING A CATALYST FROM A FIRSTSTORAGE ZONE, AND A SOLUTION OF A UREA-FORMALDEHYDE PRECODENSATE ADAPTEDTO HARDEN WHEN IN CONTACT WITH SAID CATALYST FROM A SECOND STORAGE ZONEINTO A COMMON FOAM-FROMING AND MIXING ZONE BY MEANS OF A GASEOUSPRESSURE MEDIUM, INTRODUCING SAID PRESSURE MEDIUM INTO SAID COMMON ZONETO FORM FOAM AND TO CAUSE MIXING OF SAID FOAM WITH SAID PRECONDENSATESOLUTION, AND SPRAYING THE MIXTURE PRODUCED WITH THE AID OF SAIDPRESSURE MEDIUM UPON THE OBJECT TO BE TREATED, THE PRECONDENSATESOLUTION BEING PROPELLED TO THE COMMON ZONE IMMEDIATELY PRIOR TO THESPRAYING.